1. Field of the Invention
The present invention relates to a linear module, and more particularly to a linear module with a support device.
2. Description of the Prior Art
A motion transmission apparatus used on a machine generally comprises a screw and a nut movably disposed on the screw. To prevent sagging of the screw, the motion transmission apparatus is usually provided with a support device, so that the nut can move along the same central line, which can reduce abrasion, prevent too high temperature and structure deformation, and also expand the movement range of the nut and ensure machining precision.
As shown in FIG. 1, a ball screw actuator disclosed in U.S. Pat. No. 5,720,202 comprises a rail 12 disposed at one side of the screw 11, and three support members 13 movably disposed between the screw 11 and the rail 12. The support members 13 are used to support the screw 11 and prevent sagging of the same, and the movement of the support members 13 is controlled by belts 14, 15 and pulleys 16, 17, 18 and 19.
Since the movement of the support members 13 is controlled by the belts 14, 15 and the pulleys 16, 17, 18 and 19, which makes the ball screw complicated in structure. Besides, the belts 14, 15 are likely to wear off or even broken after a certain period of time of use, which results in low reliability and high maintenance cost. Besides, the support members are provided with no covers (not shown).
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.